Bio-based environment-friendly flame retardant wallpaper and preparation method thereof

ABSTRACT

A bio-based environment-friendly flame retardant wallpaper and a preparation method thereof, including: selecting alginate fibre to be mixed with wood pulp, beating to obtain mixed size, adding dispersant and performing paper-making and drying to obtain raw paper; sequentially coating the surface of the raw paper with alginate colloid, PVC, calcium carbonate and DOP paste; performing drying, cooling, printing, and cutting into the required specification to obtain the wallpaper. The chopped alginate fibre is used as paper pulp fiber, and the catalytic cracking effect is realized by metal ions in the fibre to reduce the production of flammable gases, form an alkaline environment, produce CO 2 , dilute the flammable gases, form a solid-state barrier of metal oxides and carbonates on the surface of the fiber and achieve the flame retardant effects of little smoke, no melt drops and the like. The flame retardant oxygen index of the wallpaper is more than 30%.

FIELD OF THE INVENTION

The invention belongs to the technical field of manufacturing offunctional building decoration materials and specifically relates tobio-based environment-friendly flame retardant wallpaper and apreparation method thereof.

BACKGROUND OF THE INVENTION

Wallpaper is special processed paper for decorating walls and is widelyused in indoor decoration and the like of residences, offices,guesthouses and hotels. At present, the wallpaper has become popular toa considerable degree around the world. With the continuous improvementin production technical level, the manufacturing technology of thewallpaper is improved continuously. At present, the conventionalwallpaper is prepared by using wood pulp paper as a base material,polyvinyl chloride (PVC) as a pattern layer and performing the processsteps of printing, embossing, foaming and the like and has thecharacteristics of rich colors, diverse patterns, delicate texture, easyconstruction and the like.

However, as the wallpaper material uses a great quantity of PVC andother petrochemical raw materials, the wallpaper material is very proneto burning when a house catches fire and releases a lot of toxic smog,such as dioxins, hydrogen chloride and the like, thereby causing a greatthreat and hidden danger to life and property security of residents. Atpresent, most of the common flame retardant wallpaper adopts a way ofadding flame retardants into raw paper or a coating and a protectinglayer to achieve the purpose of flame retardance. However, the wallpaperoften has the following shortcomings: the using quantity of the flameretardants is large, and the flame retardants used by part of productsare difficult to recover and not environment-friendly (such ashalogen-containing and phosphorus-containing flame retardants); theflame retardants have poor durability, part of inorganic flameretardants are easy to remove, and part of organic flame retardants areprone to volatilization and failure after long-term use; the flameretardants are prone to moisture absorption, and the flame retardanceand the physical performances of the paper after moisture absorptiondecline obviously; and the addition of the flame retardants hasdifferent degrees of adverse effects on the durability and theprintability of the wallpaper.

SUMMARY OF THE INVENTION

The invention aims at providing bio-based environment-friendly flameretardant wallpaper and a preparation method thereof. According to themethod, alginate fibre is selected to be mixed with wood pulp, beatingis performed to prepare raw paper, the inherent flame retardantmechanism of metal ions in the alginate fibre is utilized to achieve thepurpose of flame retardance of the wallpaper without adding flameretardants, and no toxic smog is produced during the process of beingcontact with a fire source.

A first task of the invention is to provide a preparation method ofenvironment-friendly flame retardant wallpaper.

A preparation method of environment-friendly flame retardant wallpapersequentially comprises the following steps:

a. preparing raw paper: selecting alginate fibre to be mixed with fullwood pulp, beating to obtain mixed size, adding a dispersant into themixed size and performing paper-making and drying to obtain the rawpaper;

b. coating: sequentially uniformly coating the surface of the raw paperobtained in the step a with alginate colloid, PVC, calcium carbonate andDOP paste;

c. drying and cooling: drying and cooling a coating coated on thesurface of the raw paper in the step b; and

d. printing: printing a required pattern on the surface of the raw papercoating after cooling, then softening the pattern, pressing the surfaceof the raw paper coating with an embossing wheel to obtain correspondinglines, and cutting into the required specification to obtain thewallpaper.

As a preferred solution of the invention, in the step a, the alginatefibre accounts for 20-80% of the mass of bone dry pulp in the mixedsize; and the dispersant is an anion dispersant or a water-solublepolymer dispersant.

The anion dispersant is sodium fatty alcohol polyoxyethylene ethersulfate, sodium cellulose sulfate, sodium alkyl diphenyl ether sulfonateor alkyl phenyl polyoxy ethylene ether phosphate; and the water-solublepolymer dispersant is sodium alginate.

As another preferred solution of the invention, in the step b, thealginate colloid is sodium alginate, and the coating thickness aftercoating is 0.2-0.5 mm.

Preferably, in the step c, a hot air circulating system is selected todry the coating on the surface of the raw paper, the drying temperatureis 110-250° C., the drying time is 10-18 s, and the cooling time is10-30 s.

Preferably, the alginate fibre is seaweed chopped fiber with the averagelength of 3-6 mm, and the wood pulp liquid is prepared by beating fullwood pulp.

Preferably, the embossing depth of the embossing wheel is 0.2-1.0 mm.

Preferably, the preparation method of the seaweed chopped fibercomprises: filtering, defoaming and spinning a sodium alginate solutionwith the mass fraction of 2-12% under the condition that the temperatureis 15-100° C. to obtain the alginate fibre, and chopping the obtainedalginate fibre for preparation.

A second task of the invention is to provide environment-friendly flameretardant wallpaper prepared by any above-mentioned preparation method.

The invention has the following beneficial technical effects:

The invention provides environment-friendly flame retardant wallpaperand a preparation method thereof. In the aspect of selecting rawmaterials, in the prior art, the raw paper is prepared by beating thewood pulp, and various flame retardants are added separately onto theraw paper layer during coating to obtain the flame retardant wallpaper;whereas in the preparation process of the raw paper of the invention,the alginate fibre is selected to be mixed with the wood pulp, thebeating is performed to obtain the mixed size, the dispersant is addedinto the mixed size, paper-making and drying are performed to obtain theraw paper. According to the invention, on the premise of not adding anyflame retardant, the raw paper with flame retardance and durability isprepared by simple production process steps, the alginate fibre is usedas paper pulp fiber, and the catalytic cracking effect is realized bythe metal ions in the seaweed chopped fiber, so as to reduce theproduction of flammable gases, form an alkaline environment, produceincombustible CO₂, dilute the flammable gases and produce a precipitateof metal oxides and metal carbonates to cover the surface of the fiberin the paper to form a solid-state barrier; and meanwhile, the crackingtemperature of the fiber is improved by the dense chelated structure inthe alginate fiber, so as to finally achieve the flame retardant effectsof no addition of the flame retardants, no smoke and no melt drops.

According to the invention, the alginate colloid, the PVC, the calciumcarbonate and the DOP paste are used as a coating layer, and the processimproves the shape stability, the flame retardance and the processingperformance of the alginate fibre paper, improves the production speedand saves the production energy consumption of a single piece ofwallpaper. The coated surface has higher smoothness, and the non-coatedsurface has prominent natural lines of the fiber, with strongthree-dimensional sense and convenience in secondary construction.

According to the invention, the alginate fibre with natural inherentflame retardance is selected to be blended with the wood pulp for flameretardant modification, and then beating, paper-making, squeezing,drying, curling and other process steps are performed to manufacture theraw paper of the environment-friendly flame retardant wallpaper.Compared with the ordinary wallpaper, the invention has the advantagesof simple production process steps and simple structure of overlappedlayers of the wallpaper, and the wallpaper has the excellent functionsof flame retardance, no toxicity, no smoke, environment friendliness,biodegradability and the like; and the flame retardant wallpaperprepared by the invention has the flame retardant oxygen index of morethan 30%.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The invention provides bio-based environment-friendly flame retardantwallpaper and a preparation method thereof In order to enable theadvantages and the technical solutions of the invention to be clearerand more definite, the invention will be further clearly and fullyillustrated below in conjunction with the specific embodiments.

The raw materials selected by the invention are commercially available.

Embodiment 1

According to the invention, a preparation method of bio-basedenvironment-friendly flame retardant wallpaper specifically comprisesthe following steps:

(1) preparing raw paper: preparing seaweed chopped fiber with the lengthof 3 mm and 6 mm (with the mass ratio of 1:1) by wet spinning, mixingwith 6 wt % of wood pulp with the beating degree of 30° SR and beating,wherein the mass of the seaweed chopped fiber accounts for 20% of themass of bone dry paper pulp; and performing paper-making and dryingafter adding a dispersant, namely sodium cellulose sulfate with theconcentration of 0.04 wt % after dilution and 0.3 wt % of a sodiumalginate polymer solution dispersant to prepare the raw paper of thewallpaper;

(2) coating: firstly coating the 2 wt % of the sodium alginate solutionby a coating machine, performing gelation treatment by 5 wt % of acalcium chloride solution, and then uniformly coating PVA, calciumcarbonate and DOP paste on the surface of the raw paper, wherein thecoating thickness is 0.25 mm;

(3) drying: drying a coating on the surface of the raw paper through ahot air circulating system, wherein the ambient temperature for dryingis 150° C. and the drying time is 15 s;

(4) cooling: cooling and hardening the surface material by circulatingcooling water through two cooling rings, wherein the cooling process isperformed at normal temperature, and the cooling time is 10 s;

(5) printing: using different printing patterns to print the requiredpatterns on the surface of the wallpaper by using corresponding printingwheels;

(6) softening: heating the wallpaper by utilizing a heating cover tosoften the wallpaper to facilitate embossing;

(7) embossing: pressing the surface of the wallpaper by using anembossing wheel to produce corresponding line effects, wherein theembossing depth is 0.6 mm; and

(8) cutting and packaging: cutting the wallpaper into the requiredspecification and curling the product into a finished product by acurling machine according to the required size and packaging.

The flame retardant oxygen index of the flame retardant wallpaperprepared by the embodiment is tested to be 31%.

Embodiment 2

According to the invention, bio-based environment-friendly flameretardant wallpaper, and the preparation thereof specifically comprisesthe following steps:

(1) preparing raw paper: preparing seaweed chopped fiber with the lengthof 3 mm, 4 mm, 5 mm and 6 mm(with the mass ratio of 2:2:3:3) by wetspinning, mixing with 5 wt % of wood pulp with the beating degree of 40°SR and beating, wherein the mass of the seaweed chopped fiber accountsfor 50% of the mass of bone dry paper pulp; and performing paper-makingand drying after adding a dispersant, namely sodium alkyl diphenyl ethersulfonate with the concentration of 0.02 wt % after dilution and 0.4 wt% of a sodium alginate polymer solution dispersant to prepare the rawpaper of the wallpaper;

(2) coating: firstly coating the 1 wt % of the sodium alginate solutionby a coating machine, performing gelation treatment by 4 wt % of acalcium chloride solution, and then uniformly coating PVA, calciumcarbonate and DOP paste on the surface of the raw paper, wherein thecoating thickness is 0.3 mm;

(3) drying: drying a coating on the surface of the raw paper through ahot air circulating system, wherein the ambient temperature for dryingis 190° C. and the drying time is 18 s;

(4) cooling: cooling and hardening the surface material by circulatingcooling water through two cooling rings, wherein the cooling process isperformed at normal temperature, and the cooling time is 20 s;

(5) printing: using different printing patterns to print the requiredpatterns on the surface of the wallpaper by using corresponding printingwheels;

(6) softening: heating the wallpaper by utilizing a heating cover tosoften the wallpaper to facilitate embossing;

(7) embossing: pressing the surface of the wallpaper by using anembossing wheel to produce corresponding line effects, wherein theembossing depth is 0.5 mm; and

(8) cutting and packaging: cutting the wallpaper into the requiredspecification and curling the product into a finished product by acurling machine according to the required size and packaging.

The extreme oxygen index of the flame retardant wallpaper prepared bythe embodiment is tested to be 36%.

Embodiment 3

According to the invention, bio-based environment-friendly flameretardant wallpaper, and the preparation thereof specifically comprisesthe following steps:

(1) preparing raw paper: preparing seaweed chopped fiber with the lengthof 3 mm and 6 mm(with the mass ratio of 1:1) by wet spinning, mixingwith 6 wt % of wood pulp with the beating degree of 50° SR and beating,wherein the mass of the seaweed chopped fiber accounts for 60% of themass of bone dry paper pulp; and performing paper-making and dryingafter adding a dispersant, namely sodium fatty alcohol polyoxyethyleneether sulfate with the concentration of 0.04 wt % after dilution and 0.3wt % of a sodium alginate polymer solution dispersant to prepare the rawpaper of the wallpaper;

(2) coating: firstly coating the 2 wt % of the sodium alginate solutionby a coating machine, performing gelation treatment by 5 wt % of acalcium chloride solution, and then uniformly coating PVA, calciumcarbonate and DOP paste on the surface of the raw paper, wherein thecoating thickness is 0.4 mm;

(3) drying: drying a coating on the surface of the raw paper through ahot air circulating system, wherein the ambient temperature for dryingis 150° C. and the drying time is 18 s;

(4) cooling: cooling and hardening the surface material by circulatingcooling water through two cooling rings, wherein the cooling process isperformed at normal temperature, and the cooling time is 15 s;

(5) printing: using different printing patterns to print the requiredpatterns on the surface of the wallpaper by using corresponding printingwheels;

(6) softening: heating the wallpaper by utilizing a heating cover tosoften the wallpaper to facilitate embossing;

(7) embossing: pressing the surface of the wallpaper by using anembossing wheel to produce corresponding line effects, wherein theembossing depth is 0.6 mm; and

(8) cutting and packaging: cutting the wallpaper into the requiredspecification and curling the product into a finished product by acurling machine according to the required size and packaging.

The extreme oxygen index of the flame retardant wallpaper prepared bythe embodiment is tested to be 38%.

Embodiment 4

According to the invention, bio-based environment-friendly flameretardant wallpaper, and the preparation thereof specifically comprisesthe following steps:

(1) preparing raw paper: preparing seaweed chopped fiber with the lengthof 3 mm and 6 mm (with the mass ratio of 1:1) by wet spinning, mixingwith 6 wt % of wood pulp with the beating degree of 60° SR and beating,wherein the mass of the seaweed chopped fiber accounts for 80% of themass of bone dry paper pulp; and performing paper-making and dryingafter adding a dispersant, namely alkyl phenyl polyoxy ethylene etherphosphate with the concentration of 0.04 wt % after dilution and 0.3 wt% of a sodium alginate polymer solution dispersant to prepare the rawpaper of the wallpaper;

(2) coating: firstly coating the 2 wt % of the sodium alginate solutionby a coating machine, performing gelation treatment by 5 wt % of acalcium chloride solution, and then uniformly coating PVA, calciumcarbonate and DOP paste on the surface of the raw paper, wherein thecoating thickness is 0.5 mm;

(3) drying: drying a coating on the surface of the raw paper through ahot air circulating system, wherein the ambient temperature for dryingis 250° C. and the drying time is 18s ;

(4) cooling: cooling and hardening the surface material by circulatingcooling water through two cooling rings, wherein the cooling process isperformed at normal temperature, and the cooling time is 30 s;

(5) printing: using different printing patterns to print the requiredpatterns on the surface of the wallpaper by using corresponding printingwheels;

(6) softening: heating the wallpaper by utilizing a heating cover tosoften the wallpaper to facilitate embossing;

(7) embossing: pressing the surface of the wallpaper by using anembossing wheel to produce corresponding line effects, wherein theembossing depth is 0.5 mm; and

(8) cutting and packaging: cutting the wallpaper into the requiredspecification and curling the product into a finished product by acurling machine according to the required size and packaging.

The extreme oxygen index of the flame retardant wallpaper prepared bythe embodiment is tested to be 41%.

It should be understood that the above description of the preferredembodiments is relatively detailed, but it cannot be considered to limitthe protection scope of the inventive patent. Those of ordinary skill inthe art can make substitutions, simple combinations and other variousmodifications without departing from the scope protected by the claimsof the invention under the inspiration of the invention, and theprotection scope claimed by the invention should be defined by theappended claims.

1. A preparation method of environment-friendly flame retardantwallpaper, sequentially comprising the following sequential steps: a.preparing raw paper: selecting alginate fibre to be mixed with full woodpulp, beating to obtain mixed size, adding a dispersant into the mixedsize and performing paper-making and drying to obtain the raw paper; b.coating: sequentially uniformly coating the surface of the raw paperobtained in the step a with alginate colloid, PVC, calcium carbonate andDOP paste; c. drying and cooling: drying and cooling a coating coated onthe surface of the raw paper in the step b; and d. printing: printing arequired pattern on the surface of the raw paper coating after cooling,then softening the pattern, pressing the surface of the raw papercoating with an embossing wheel to obtain corresponding lines, andcutting into the required specification to obtain the wallpaper.
 2. Thepreparation method of the environment-friendly flame retardant wallpaperaccording to claim 1, wherein, in the step a, the alginate fibreaccounts for 20-80% of the mass of bone dry pulp in the mixed size; andthe dispersant is an anion dispersant or a water-soluble polymerdispersant.
 3. The preparation method of the environment-friendly flameretardant wallpaper according to claim 1, wherein in the step b, thealginate colloid is sodium alginate, and the coating thickness is0.2-0.5 mm.
 4. The preparation method of the environment-friendly flameretardant wallpaper according to claim 1, wherein in the step c, a hotair circulating system is selected to dry the coating on the surface ofthe raw paper, the drying temperature is 110-250° C., the drying time is10-18 s, and the cooling time is 10-30 s.
 5. The preparation method ofthe environment-friendly flame retardant wallpaper according to claim 1,wherein in the step d, the embossing depth of the embossing wheel is0.2-1.2 mm.
 6. The preparation method of the environment-friendly flameretardant wallpaper according to claim 2, wherein the alginate fibre isseaweed chopped fiber with the average length of 3-6 mm.
 7. Thepreparation method of the environment-friendly flame retardant wallpaperaccording to claim 6, wherein the preparation method of the seaweedchopped fiber comprises: filtering, defoaming and spinning a sodiumalginate solution with the mass fraction of 2-12% under the conditionthat the temperature is 15-100° C. to obtain the alginate fibre, andchopping the obtained alginate fibre for preparation. 8.Environment-friendly flame retardant wallpaper prepared by thepreparation method according to claim
 1. 9. Environment-friendly flameretardant wallpaper prepared by the preparation method according toclaim
 2. 10. Environment-friendly flame retardant wallpaper prepared bythe preparation method according to claim
 3. 11. Environment-friendlyflame retardant wallpaper prepared by the preparation method accordingto claim
 4. 12. Environment-friendly flame retardant wallpaper preparedby the preparation method according to claim
 5. 13. Environment-friendlyflame retardant wallpaper prepared by the preparation method accordingto claim
 6. 14. Environment-friendly flame retardant wallpaper preparedby the preparation method according to claim 7.